The present invention relates to an air intake system of a multi-cylinder internal-combustion engine, comprising two cylinder tanks, cylinders of one respective cylinder bank being connected by suction pipes to a respective resonance container associated therewith, the resonance containers being combined by a connecting pipe and having suction pipe extensions extending in sections inside the respective resonance containers with sliding sleeves which, as a function of operating parameters of the internal-combustion engine, are adjustable between inlet openings of the suction pipes from a first spaced position into a second non-spaced position.
The air intake system of unpublished DE-P 43 15 129.9-13 exemplifies increasing the mean pressure over the whole rotational speed range. Thus, an increased amount of fresh air is supplied to each cylinder which causes a clear improvement of the volumetric efficiency.
It is an object of the present invention to optimize and improve this known air intake system constructionally and with respect to manufacturing techniques while maintaining good functioning thereof.
This object has been achieved according to the present invention by providing that a plurality of sliding sleeves of one cylinder bank are combined to form a constructional unit configured to cooperate with an adjusting device, and the sliding sleeves surround the suction pipe extension sections configured as inserts.
The principal advantages achieved with the present invention are that the sliding sleeves are assigned to a constructional unit which is easy to manufacture. Thus, the sliding sleeves, according to their function, surround the inserts which are integrated into the air intake system and have a simple construction. The tolerance-compensating holding of the inserts ensures a good functioning of the sliding sleeves. The fastening of the respective insert on the housing of the air intake system by way of a collar and a snap ring is cost effective and operationally reliable. The operational reliability is also promoted by the special pairing of materials. That is, the housing and the sliding sleeves are made of aluminum alloy, and the inserts are made of iron-metallic material, such as thin sheet metal. The adjusting device is applied in a center of gravity line of the constructional unit, to achieve favorable operating conditions. Finally, the slot opening of the lever and the cylindrical pin of the constructional unit represent a transmission element which is easy to implement but is highly effective.